The present invention concerns a mantrap. It has a demarcation in the shape of a segment of an arc at one side of a passage. The open side of the demarcation faces the other side of the passage. The demarcation extends along a prescribed angle of circumference. It has a barrier element that rotates around a vertical axis positioned approximately in the center of the demarcation. The barrier element is provided with leaves. The leaves extend out from the axis of rotation while including preferably equal angles and consist of grating rods positioned separated and one above another. The mantrap also has a barrier rake extending out from the axis of the barrier element to the other side of the passage. The barrier rake consists of grating rods positioned displaced from the grating rods in the leaves and one above another. The barrier-rake rods allow unimpeded rotation of the barrier element.
A known barrier element is described in sales literature published by the present applicants. It rotates around an upright axis. It consists of a turnstile with three leaves displaced in relation to one another at angles of 120.degree.. A demarcation in the shape of an arc of a circle is positioned on one side of the passage and extends over a circumferential angle of approximately 120.degree.. The system is designed to ensure that, as long as the barrier element is symmetrical to the demarcation, any gaps that occur between the ends of the demarcation and the ends of the barrier-element leaves will be of a size that does not allow a person to pass through. The blockage on the other side of the passage that accommodates the mantrap on the other hand is what is called a comb rake. It also consists of separated grating rods positioned one over another. They are positioned displaced from the grating rods in the leaves of the barrier element in the form of a turnstile such that, when the barrier element is rotated around its upright axis the grating rod in the leaves can always pass unimpeded between adjacent grating rods in the blockage.
The known mantrap can be equipped with a simple backward-rotation prevention mechanism or with an electromechanical locking mechanism for the turntable and accordingly rotate in one or both senses. The mantrap can accordingly be employed either as an entry mantrap, as an exit mantrap, or as a combination of both.
Such mantraps are often employed for the external security of industrial premises and are integrated into the fences, walls, or other enclosures that surround them. One problem of the known mantrap is that it does not allow for the transport of heavy burdens. Another is that it does not comply with the demand for escape routes in the event of emergencies. Additional passages must accordingly be provided in the form of gates for transporting burdens and for escape routes. The gates are positioned in the enclosures adjacent to the mantraps and can be opened when necessary. This is costly. It is also problematic in the event of emergencies in that the escape routes differ from the regular passages.